Hydrothermally Synthesized WS $_{\text{2}}$ -QDs/Si (0-D/3-D) Vertical Heterojunction for an Efficient Wide Spectral (UV–Vis–NIR) Photodetection

High-performance broadband photodetectors (PDs) based on transition metal dichalcogenides (TMDs) materials are highly desired for cutting-edge optoelectronics to address the issue of the complexity involved with conventional materials. Despite the reports of the fabrication of broadband PDs based on TMDs, the challenge of employing a less complicated and low-cost fabrication process without compromising performance still needs to be addressed. Hence, the present article reports the fabrication of an economical, facile, water-soluble (nontoxic), and low-temperature operated hydrothermally synthesized WS $_{\mathbf{\text{2}}}$ -quantum dots (QDs)/Si vertical heterojunction-based broadband PD. The fabricated PD demonstrated to operate at a broad spectrum ranging from 365 to 950 nm (UV–Vis–NIR) and showed a peak responsivity value of 90.21 A/ W, external quantum efficiency (EQE) of 30 648.55%, and detectivity of 2.08 $\times$ 10 $^{\mathbf{\text{14}}}$ Jones at 365 nm. The PD also demonstrated a fast photoresponse speed with a rise and fall time of 44.3 and 39.2 ms, respectively.